Milk-sterilizing apparatus.



J. MERIB. MILK STERILIZING APPARATUS. APPLICATION FILED 1030.18, 1912.

Patented. Feb. 23, 1915.

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JEAN M'ERIE, OF PARIS, FRANCE.

MILK-STERILIZING APPARATUS.

Specification of Letters Patent.

Patented Feb. 23, 1915.

I Application filed December 18, 1912. SerialNo. 737,412.

The methods heretofore employed for preventing the fermentation and decomposition of milk to enable it to be kept for a time for stora e or for transportation do not give entire y satisfactory results. The addition of antiseptics is a method usually condemned. Pasteurization is insuilicient to preserve milk for a long time, and does not insure that it is absolutely innocuous. It is therefore necessary to employ sterilization but the process of sterilization as heretofore carried out presents numerous disadvantages: it imparts a cooked taste to the milk, causes it to assume a slightly red tint, transforms a part of the fatty, matters lnto butter and decreases the digestive properties of the milk.

The present invention relates to an improved process for treating milk whereby the hereinbefore mentioned disadvantages are entirely avoided. This process 15 substantially characterized by the following points:

1. The milk is progressively heated to the temperature of sterilization by passing through a heat exchanger and through a calefactor where it is submitted to a pressure sufficient to balance the tension of the gases; the cross sectional area of the milk conveying conduits or passages being constant throughout their length. In this way, at no moment whatever can be produced (a) stoppages in the circulation of the whole mess of themilk, stoppages which might cause the cooking of the milk; (6) expansions which would determine the liberation of the gases contained in the milk and would deprive it of its properties.

2. The milk is never in direct contact with the source of heat. It is progressively heated first by the heat carried away by the milk already sterilized and then by its passage in a calefactor where it-remains until the temperature of sterilization is-reached'; in this calefactor a mass of water is interposed between the source of heat and the milk, thus avoiding the decomposition of the milk by direct thermal action. By means of these arrangements, there is always only a difference of temperature of a few degrees between the milk and the wall giving up the heat to the same. The milk treated in these conditions preserves its characteristic color, its natural taste and all its digestive properties. The sterilization obtained is however complete. 7

The device preferably used for putting into practice this improved process comprises a sterilizer in combination with a pump and a closed tank or compressor. The pump is adapted to feed the sterilizer; the compressor-tank serves for the regulation of the pressure. The sterilizing apparatus is formed by the combination of two known elements but constructed in such a way that their conduits or passages and the piping which connect them is of equivalent cross section, that is to say constant throughout the path of the milk. These two elements are:

l. A heat exchanging apparatus constituted by two sheets of copper wound around a central core, so as to form two independent conduits or passages open the one toward the top and the other toward the bottom of the apparatus. The first of these conduits serves for the circulation of the hot liquid and the second for the circulation of the cold liquid which progresses in reverse direction to that of the hot liquid. One of the main features of the present invention con sists in the improvement in the sizes and shape of the spiral heat exchanger, so that it may be easily handled, that access may be had to all its parts and that it can be readily cleaned which is of the greatest. importance in the dairy industry. The conduits or passages of the heat exchanger are of large. area but of small height so that the apparatus may be easily and completely cleaned and capable of withstanding moderately high pressures. The heat exchanging apparatus should preferably consist of a plurality of similar elements connected together first in parallel then in series.

2. A calefactor constituted by a water bath filled with water in which is immersed a coil constituted by horizontal tubes set on two opposite walls and in communication together through removable doors forming successive intercommunication for the whole of the tubes. The water-bath must form a powerful thermal accumulator for insuring the regularity of the heating; for that pur-- pose it must be constructed so as to have a capacity equal to six times that of the coil. One form of the apparatus is illustrated in the accompanying drawings, in which:

Figure 1 is a vertical section of the heat exchanging apparatus. Fig. 2 is a horizontal section made accordingto line A-A of F i'g. 1. 3 is a horizontal section of the calefactor. Fig. 4 is a diagrammatic view showing the circulation of the milk.

As illustrated in the drawings, the heat exchanging apparatus consists of a plurality of similar elements connected together first in parallel then in series; each element is constituted by two sheets of tinned copper a and I), wound in spiral. These sheets are connected together by copper strips 0 soldered with the same and closing the element at the top and bottom alternately, as shown in Fig. 1. In this way the element comprises two distinct conduitsorpaesages d and 6 open the one toward the bottom and the other toward the top. Two consecutive elements are separated by -two sheets of India rubber f or other elastic or plastic m'aterialbetween which is arranged .a copper late 9. Above and below each series of e ements are arranged two strong plates 72. and i which may be connected and held together by means of bolts which pass through the whole assemblage.

j is the inlet-pipe leading in the milk to be sterilized into the passa e e of each element through inlets 7' he milk passes right through the'passage 'e and out through outlets I0 and is led away to the calefactor through a pipe is. The sterilized milk is delivered from the calefactor by'means of a pipe Z and is-led through inlets Z into the passages d; after passing through said passa es d it is led away by a pipe m.

he calefactor is constituted by a square boiler 11. which may be heated in an suitable manner; This boiler is traversed y parallel tubes o exterior ly connected by detachable connections p which enable the tubes to be cleaned. The tubes thus connected together form a coil immersed in the water of-the boiler. This water forms a waterbath or heat accumulator of large volume whose temperature may be easily adjusted so as to remain constant.

The liquid to be sterilized coming from the heatrexchanging apparatus enters at one end of the coil 0 and passes out at its other end without stoppage. The constant speed circulation in the heat-exchanging appa-- ratus and in the calefactor is insured by an invariable pressure within the passages whose cross section 15 equivalent as well in the 'two' parts of the apparatus as. in the piping connecting them. The running off of the liquid under invariable pressure is obtained by means of a pump it, a tank u and two cocks rand 1? respectively placed the one at the inlet and the other at the outletof the apparatus. Each cock is provided with a control gage s and 8 The inlet cock being wide open and the gage indicating a determined pressure, according to the temperature of sterilization, the operation of the outlet cock allows of adjusting the runnin off of the liquid to the outflow required. he pressure at the inlet being v maintained invariable, the pressure at the outlet is also invariable for a constant outflow.' The milk thus treated is then hermetically inclosed in metallic bottles or vessels which have been previously sterilized.

I claim:

1. In an' apparatus for sterilizing milk, a heat-exchanging apparatus comprising a conduit in which passes the milk already sterilized, a conduit through which passes the milk to be sterilized, which is heated progressively, a calefactor, a conduit in said calefactor, the conduits of the heat-exchange ing apparatus and that of the calefactor being of equal and constant'cross section so as to avoid any expansion of the milk, and means to produce a constant pressure during the whole operation.

j 2. In an apparatus for sterilizing milk, a heat-exchanging apparatus comprising a conduit having the form of a spiral, in which .passes the milk already sterilized, a conduit having the form of a spiral through which passes the milk to be'sterilized, which is heated progressively, a calefactor, a conduit in said calefactor, the conduits of the calefactor being of equal and constant cross section so as to avoid any expansion of the milk, and means to produce a constant pressure during the whole operation. I

3. In an apparatus for sterilizing milk, a heat-exchanging apparatus comprlsing a conduit in which asses the milk already sterilized, a conduit'through which passes the milk to be sterilized, which is heated progressively, a calefactor, a conduit in said calefactor heated in a water-bath, the conduits of the heat-exchanging ap aratus and that of the calefactor being 0 equal and constant cross section so asto avoid any expansion of the milk, and means to produce a constant pressure during the whole operation.

4. In an apparatus for sterilizing milk, a heat-exchanging apparatus, a calefactor, a plurality of similar elements in said heat exchanging apparatus, and plates covered with elastic sheets separating said elements.

5. In an apparatus for sterilizing milk, a heat exchanger having conduits, a water bath calefactor, and tubes in said calefactor proved milk sterilizing apparatus signed by fOIiIIIKIiHg a1 CODdlit for the circt'lulation of the me this third day of December 1912. mi sai con uit aving t e same cross section as the conduits of the exchanger, and JEAN MERIE' 5 means for producing a. constant pressure Witnesses:

during the Whole operation. LUCIEN MEMMINGER,

The foregoing specification of my im- RENE: Tmmo'r. 

